1. Field
The following description relates to an optical recording method and an optical recording device, and more particularly, to a strategy for writing information to an optical disc.
2. Description of Related Art
Optical disc drives (ODDs) may be specialized to reduce a recording time and to have good reproduction characteristics. In order to store information written to an optical disc for a long duration of time while not deteriorating the optical disc, a good-quality optical disc is required, and write characteristics of an optical disc drive that writes data to the optical disc should be excellent.
General optical discs have a large difference in write quality due to their storage life spans. One of the reasons for the large difference in quality is that an optical disc is rotated while vibrating in a vertical direction. As a result, uniform optical power may not reach a write layer.
To cope with the vibration, an actuator typically follows disc vibration using a focus servo system. Even with the focus servo system, a difference in write quality occurs in optical discs because thicknesses of reflective layers of optical discs are not uniform. For example, reflective layers of optical discs may be formed by a physical deposition method, such as sputtering. As a result, thicknesses of inner regions, intermediate regions, and outer regions thereof may not be uniform.
Generally, a thickness of a reflective layer of an intermediate region of an optical disc is larger than a thickness of a reflective layer in inner and outer regions of the optical disc. As a result, if information is written onto an optical disc from the inner region to the outer region using the same optical power, excessive optical power is set in the inner and outer regions of the optical disc.
To cope with the varying thickness, an optical power calibration (OPC) operation of an ODD is performed before information is written onto the optical disc. However, in the OPC operation, optical output is optimized in the intermediate region of the optical disc, which results in lowering the long-term storability of information written in the inner and outer regions of the optical disc because of excessive optical output by the inner and outer regions of the optical disc.